Stack battery pack for electric vertical take-off and landing aircraft

ABSTRACT

A stack battery pack for an electric vertical take-off and landing aircraft includes a first pouch cell comprising a first top surface and a first bottom surface, a second pouch cell comprising a second top surface and a second bottom, wherein the first pouch cell and the second pouch cell are aligned such that the first bottom surface is in contact with the second top surface, an ejecta barrier located between the first pouch cell and the second pouch cell, wherein the ejecta barrier is configured to be substantially impermeable to a cell ejecta from the first pouch cell, and a vent configured to vent the cell ejecta, wherein the stack battery pack is configured to power a propulsor component.

FIELD OF THE INVENTION

The present invention generally relates to the field of transportationand aircraft. In particular, the present invention is directed to astack battery pack for electric vertical take-off and landing.

BACKGROUND

Manned electric vertical take-off and landing (eVTOL) aircraft flightfolds the promise of uncongested commuted roadways and air-travelwithout the presently concomitant fossil fuel usage. eVTOL aircraftflight requires electric energy storage, for example by way of batterycells. However, battery cells can suffer from thermal runaway such aswhen a battery cell overheats causing conditions that contribute tofurther overheating of the battery cell in an uncontrolled positivefeedback loop. Conflagration resulting from thermal runaway of a singlebattery cell is further fueled when thermal runaway progresses to secondor third battery cell.

SUMMARY OF THE DISCLOSURE

In an aspect, a stack battery pack for an electric vertical take-off andlanding aircraft includes a first pouch cell comprising a first topsurface and a first bottom surface, a second pouch cell comprising asecond top surface and a second bottom surface, wherein the first pouchcell and the second pouch cell are aligned such that the first bottomsurface is in contact with the second top surface, an ejecta barrierlocated between the first pouch cell and the second pouch cell, whereinthe ejecta barrier is configured to be substantially impermeable to acell ejecta from the first pouch cell, and a vent configured to vent thecell ejecta, wherein the stack battery pack is configured to power apropulsor component.

In another aspect, a method of manufacture for an electric verticaltake-off and landing aircraft includes receiving a first pouch cellcomprising a first top surface and a first bottom surface, obtaining asecond cell pouch comprising a second top surface and a second bottomsurface, wherein the first pouch cell and the second pouch cell arealigned such that the first bottom surface is in contact with the secondtop surface, locating an ejecta barrier between the first pouch cell andthe second pouch cell, wherein the ejecta barrier is configured to besubstantially impermeable to the cell ejecta from the first pouch cell,configuring a vent to vent the cell ejecta from the first pouch cell,and configuring the stack battery pack to power a propulsor component.

These and other aspects and features of non-limiting embodiments of thepresent invention will become apparent to those skilled in the art uponreview of the following description of specific non-limiting embodimentsof the invention in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, the drawings show aspectsof one or more embodiments of the invention. However, it should beunderstood that the present invention is not limited to the precisearrangements and instrumentalities shown in the drawings, wherein:

FIG. 1 is a block diagram illustrating an exemplary stack battery packfor an electric vertical take-off and landing aircraft;

FIG. 2 is a block diagram of an exemplary stack battery pack forpreventing progression of thermal runaway between modules;

FIG. 3 is a schematic representation of an exemplary electric verticaltake-off and landing vehicle;

FIG. 4 is a block diagram of an exemplary battery management system;

FIG. 5 is an illustration of a sensor suite in partial cross-sectionalview;

FIG. 6 is a flow diagram of an exemplary method of manufacture for astack battery pack for an electric vertical take-off and landingaircraft; and

FIG. 7 is a block diagram of a computing system that can be used toimplement any one or more of the methodologies disclosed herein and anyone or more portions thereof.

The drawings are not necessarily to scale and may be illustrated byphantom lines, diagrammatic representations and fragmentary views. Incertain instances, details that are not necessary for an understandingof the embodiments or that render other details difficult to perceivemay have been omitted.

DETAILED DESCRIPTION

At a high level, aspects of the present disclosure are directed tosystems and methods for a stack battery pack for an electric verticaltake-off and landing aircraft. In an embodiment, an electric verticaltake-off and landing vehicle (eVTOL) may include a stack battery packfor preventing progression of thermal runaway between modules. Someembodiments include methods of manufacture for a stack battery pack forpreventing progression of thermal runaway between modules. Aspects ofthe present disclosure allow for battery cells to be stacked such thatthe top of one battery cell is in contact with the bottom of theadjacent battery cell.

Aspects of the present disclosure can be used to contain cell ejectaresulting from thermal runaway of a first battery cell, therebypreventing the cell ejecta from contributing to thermal runaway of asecond battery cell. Aspects of the present disclosure can also be usedto contain cell ejecta resulting from heating (e.g., non-thermal runawayconditions) of a first battery cell. This is so, at least in part,because materials vented from a battery cell prior to thermal runawaymay cool and condense on neighboring battery cells; this condensate maythen ignite when in presence of increased temperature and/or oxidizer,for example when a nearby battery cell experience thermal runaway.

Aspects of the present disclosure allow for vented materials from abattery cell to be isolated away from other battery cells as they arebeing vented. This may prevent cell ejecta, electrolyte vapors, off-gas,and the like thereof from a first battery cell from influencing thermalconditions of a second battery cell. Further aspects of the presentdisclosure may also be used with one or more pouch or prismatic batterycells. In some cases, pouch battery cells may allow for packagingefficiencies in excess of 90% or even 95% compared to other (e.g., can)battery cell packaging systems. Additionally, in some cases, pouchbattery cells may be configured to reduce a weight of a stack batterypack. In order to realize the potential offered by electric verticaltake-off and landing (eVTOL) aircraft batteries must be available thatare space and weight efficient and above all safe and reliable. In someembodiments, battery packs according to the present disclosure may beconfigured for use in eVTOL aircraft and may help to one day fullyrealize the potential of eVTOL flight. Exemplary embodimentsillustrating aspects of the present disclosure are described below inthe context of several specific examples.

Referring now to the drawings, FIG. 1 illustrates a block diagram of anexemplary stack battery pack 100 for an electric vertical take-off andlanding aircraft. Stack battery pack 100 includes a first pouch cell104. As used in this disclosure, “pouch cell” is a battery cell ormodule that includes a pouch. In some cases, a pouch cell may include orbe referred to as a prismatic pouch cell, for example when an overallshape of pouch is prismatic. In some cases, a pouch cell may include apouch which is substantially flexible. Alternatively or additionally, insome cases, pouch may be substantially rigid. First cell pouch 104includes a first top surface. As used in this disclosure a “top surface”is an upper surface of a pouch cell, wherein the surface is oriented ata position that is furthest from the ground. Additionally oralternatively, first cell pouch 104 includes a first bottom surface. Asused in this disclosure a “bottom surface” is a lower surface of a pouchcell, wherein the surface is oriented at a position that is closest tothe ground. In an embodiment, and without limitation, first cell pouch104 may include a first pair of electrodes 108. As used in thisdisclosure a “pair of electrodes” is a positive and a negativeelectrode, wherein an electrode is an electrically conductive element.For example, and without limitation, first pair of electrodes 108 mayinclude one or more braided wires, solid wires, metallic foils,circuitries, such as but not limited to printed circuit boards, and thelike thereof. In an embodiment, and without limitation, first pouch cell104 may include a first pair of foil tabs 112, wherein the first pair offoil tabs 112 may be in electric communication and/or electricallyconnected to first pair of electrodes 108. In an embodiment, and withoutlimitation, first pair of foil tabs 112 may be bonded in electriccommunication with and/or electrically connected to pair of first pairof electrodes 108 by any known method, including without limitationwelding, brazing, soldering, adhering, engineering fits, electricalconnectors, and the like. In some cases, first pair of foil tabs 112 mayinclude a cathode and an anode. In some cases, an exemplary cathode mayinclude a lithium-based substance, such as lithium-metal oxide, bondedto an aluminum foil tab. In some cases, an exemplary anode may include acarbon-based substance, such as graphite, bonded to a copper tab. Firstpouch cell 104 may include a first insulator layer 116. As used in thisdisclosure, an “insulator layer” is an electrically insulating materialthat is substantially permeable to battery ions, such as withoutlimitation lithium ions. In some cases, insulator layer may be referredto as a separator layer or simply separator. In an embodiment, andwithout limitation, first insulator layer 116 may be configured toprevent electrical communication directly between first pair of foiltabs 112 such as, but not limited to a cathode and an anode. In somecases, first insulator layer 116 may be configured to allow for a flowions across it. First insulator layer 116 may consist of a polymer, suchas without limitation polyolifine (PO). First insulator layer 116 maycomprise pours which are configured to allow for passage of ions, forexample lithium ions. In some cases, pours of a PO first insulator layer116 may have a width no greater than 100 μm, 10 μm, or 0.1 μm. In somecases, a PO first insulator layer 116 may have a thickness within arange of 1-100 μm, or 10-50 μm.

With continued reference to FIG. 1 , first cell pouch 104 may include afirst pouch 120. First pouch 120 may be configured to substantiallyencompass first pair of foil tabs 112 and a portion of first insulatorlayer 116. In some cases, first pouch 120 may include a polymer, such aswithout limitation polyethylene, acrylic, polyester, and the like. In anembodiment, and without limitation, first pouch 120 may be coated withone or more coatings. For example, in some cases, first pouch 120 mayhave an outer surface coated with a metalizing coating, such as analuminum or nickel containing coating. In some cases, pouch coating beconfigured to electrically ground and/or isolate pouch, increase pouchesimpermeability, increase pouches resistance to high temperatures,increases pouches thermal resistance (insulation), and the like.Additionally or alternatively, first pouch cell 104 may include a firstelectrolyte 124, wherein first electrolyte 124 may be located withinfirst pouch 120. In some cases, first electrolyte 124 may comprise aliquid, a solid, a gel, a paste, and/or a polymer. In an embodiment, andwithout limitation, first electrolyte 124 may wet and/or contact oneand/or both of first pair of foil tabs 112.

Still referring to FIG. 1 , stack battery pack 100 includes a secondpouch cell 128, wherein a pouch cell is a battery cell or module thatincludes a pouch as described above. Second pouch cell 128 includes asecond top surface, wherein a top surface is an upper surface of a pouchcell, wherein the surface is oriented at a position that is furthestfrom the ground as described above. Additionally or alternatively,second pouch cell 128 includes a second bottom surface, wherein a secondbottom surface is a lower surface of a pouch cell, wherein the surfaceis oriented at a position that is closest to the ground as describedabove. In an embodiment, and without limitation, second pouch cell 128may include a second pair of electrodes 132, wherein a pair ofelectrodes is a positive and a negative electrode, wherein an electrodeis an electrically conductive element as described above. In anotherembodiment, and without limitation, second pouch cell 128 may include asecond pair of foil tabs 136, wherein the second pair of foil tabs 136may be in electric communication and/or electrically connected to secondpair of electrodes 132. In an embodiment, and without limitation, secondpair of foil tabs 136 may be bonded in electric communication withand/or electrically connected to pair of first pair of electrodes 132 byany known method, including without limitation welding, brazing,soldering, adhering, engineering fits, electrical connectors, and thelike. Additionally or alternatively, and without limitation, secondpouch cell 128 may include a second insulator layer 140, wherein aninsulator layer is an electrically insulating material that issubstantially permeable to battery ions, such as without limitationlithium ions, as described above. In some cases, insulator layer may bereferred to as a separator layer or simply separator. In an embodiment,and without limitation, second insulator layer 140 may be configured toprevent electrical communication directly between second pair of foiltabs 136 such as, but not limited to a cathode and an anode. In somecases, second insulator layer 140 may be configured to allow for a flowions across it. Second insulator layer 140 may consist of a polymer,such as without limitation polyolifine (PO). Second insulator layer 140may comprise pours which are configured to allow for passage of ions,for example lithium ions. In some cases, pours of a PO second insulatorlayer 140 may have a width no greater than 100 μm, 10 μm, or 0.1 μm. Insome cases, a PO second insulator layer 140 may have a thickness withina range of 1-100 μm, or 10-50 μm.

With continued reference to FIG. 1 , second cell pouch 128 may include asecond pouch 144. Second pouch 144 may be configured to substantiallyencompass second pair of foil tabs 136 and a portion of second insulatorlayer 140. In some cases, second pouch 144 may include a polymer, suchas without limitation polyethylene, acrylic, polyester, and the like. Inan embodiment, and without limitation, second pouch 144 may be coatedwith one or more coatings. For example, in some cases, second pouch 144may have an outer surface coated with a metalizing coating, such as analuminum or nickel containing coating. In some cases, pouch coating beconfigured to electrically ground and/or isolate pouch, increase pouchesimpermeability, increase pouches resistance to high temperatures,increases pouches thermal resistance (insulation), and the like.Additionally or alternatively, second cell pouch 128 may include asecond electrolyte 148, wherein second electrolyte 148 may be locatedwithin second pouch 144. In some cases, second electrolyte 148 maycomprise a liquid, a solid, a gel, a paste, and/or a polymer. In anembodiment, and without limitation, second electrolyte 148 may wetand/or contact one and/or both of second pair of foil tabs 136.

In an embodiment, and still referring to FIG. 1 , first pouch cell 104and second pouch cell 128 may be aligned such that first bottom surfaceof first pouch cell 104 is in contact with second top surface of secondpouch cell 128. As used in this disclosure “contact” is a state and/orcondition of physical touching. In an embodiment, and withoutlimitation, contact may include electrical and/or non-electricalcontact. For example, and without limitation, first pouch cell 104 andsecond pouch cell 128 may be aligned along a vertical axis 152. As usedin this disclosure a “vertical axis” is an axis that extends from abottom surface of a pouch cell to a top surface of a pouch cell. In anembodiment, and without limitation, first pouch cell 104 and secondpouch cell 128 may be aligned along vertical axis 152 such that thefirst bottom surface of first pouch cell 104 and second bottom surfaceof second pouch cell 128 are in contact.

With continued reference to FIG. 1 , stack battery pack 100 includes anejecta barrier 156. In an embodiment, and without limitation, ejectabarrier 156 may be located substantially between a first pouch cell 104and second pouch cell 128. As used in this disclosure, an “ejectabarrier” is any material or structure that is configured tosubstantially block, contain, or otherwise prevent passage of cellejecta. For example, ejecta barrier 156 may substantially encapsulatefirst pouch cell 104 and/or second pouch cell 128. As used in thisdisclosure, “ejecta” is any material that has been ejected, for examplefrom a battery cell. In some cases, cell ejecta may be ejected duringthermal runaway of a battery cell. Alternatively or additionally, insome cases, cell ejecta may be ejected without thermal runaway of abattery cell. In some cases, cell ejecta may include lithium-basedcompounds. Alternatively or additionally, cell ejecta may includecarbon-based compounds, such as without limitation carbonate esters.Cell ejecta may include matter in any phase or form, including solid,liquid, gas, vapor, and the like. In some cases, cell ejecta may undergoa phase change, for example, and without limitation, cell ejecta may bevaporous as it is initially being ejected and then cool and condenseinto a solid or liquid after ejection. In an embodiment, and withoutlimitation, ejecta barrier 156 may be configured to prevent materialsejected from first pouch cell 104 from coming into contact with secondpouch cell 128. For example, and without limitation, ejecta barrier 156is substantially impermeable to cell ejecta from first pouch cell 104and/or one or more additional pouch cells. In some embodiments, ejectabarrier 156 may include titanium. As used in this disclosure“substantially impermeable” is a characteristic of ejecta barrier thatdenotes the barrier prevents passage of one or more gases, fluids,and/or solids. In an embodiment, and without limitation, substantiallyimpermeable may include a barrier being fully impermeable. For example,and without limitation, ejecta barrier 156 may be fully impermeable as afunction of restricting and/or preventing all passage of cell ejectaacross a barrier. As a further non-limiting example, ejecta barrier 156may be impermeable as a function of blocking and/or halting all passageof cell ejecta across a barrier. In an embodiment, and withoutlimitation, substantially impermeable may include ejecta barrier 156being selectively impermeable, wherein a magnitude and/or percentage ofcell ejecta may be allowed to pass and/or permeate ejecta barrier 156.For example, and without limitation, ejecta barrier 156 may beselectively impermeable for a fluid as a function of allowing 20% of afluid to permeate, wherein ejecta barrier 156 may be impermeable to agas such as carbon monoxide, wherein no carbon monoxide may permeateejecta barrier 156.

Still referring to FIG. 1 , ejecta barrier 156 may include a carbonfiber element. As used in this disclosure a “carbon fiber element” is abarrier comprising an element of carbon. For example and withoutlimitation, carbon fiber element may include one or more carbon fibersheets, carbon fiber supported metals, carbon fiber bands, and the likethereof. In an embodiment, and without limitation, carbon fiber elementmay include one or more carbon fibers comprising 5-10 micrometers indiameter. In another embodiment, and without limitation, carbon fiberelement may comprise high stiffness, high tensile strength, low weightto strength ratio, high chemical resistance, high temperature tolerance,and/or low thermal expansion. In an embodiment, and without limitation,carbon fiber element may include one or more composites such as aplastic resin, polymer, graphite, and the like thereof. In some cases,ejecta barrier 156 may include at least a one of a lithophilic or alithophobic material or layer, configured to absorb and/or repellithium-based compounds. In some cases, ejecta barrier 156 may comprisea lithophilic metal coating, such as silver or gold. In some cases,ejecta barrier 156 may be flexible and/or rigid. In some cases, ejectabarrier 156 may include a sheet, a film, a foil, or the like. Forexample in some cases, ejecta barrier 156 may be between 25 and 5,000micrometers thick. In some cases, ejecta barrier 156 may have a nominalthickness of about 2 mm. Alternatively or additionally, in some cases,ejecta barrier 156 may include rigid and/or structural elements, forinstance which are solid. Rigid ejecta barriers 156 may include metals,composites and the like. In some cases, ejecta barrier 156 may befurther configured to structurally support first pouch cell 104 and/orsecond pouch cell 128. For example in some cases, first pouch cell 104and/or second pouch cell 128 may be mounted to a rigid ejecta barrier156.

With continued reference to FIG. 1 , stack battery pack 100 mayadditionally include a vent 160. In some cases, vent 160 may beconfigured to vent cell ejecta from first pouch cell 104. In some cases,at least a vent 160 may be configured to vent cell ejecta along a flowpath 164. Flow path 164 may substantially exclude second pouch cell 128,for example fluids such as gases liquids, or any material that acts as agas or liquid, flowing along the flow path 164 may be cordoned away fromcontact with second pouch cell 128. For example flow path 164 may beconfigured to not intersect with any surface of second pouch cell 128.As a further non-limiting example, flow path 164 may be configured toextend from first pouch cell 104 to an exterior location. As used inthis disclosure an “exterior location” is a location and/or place thatexists outside of stack battery pack 100. In an embodiment, and withoutlimitation, exterior location may include a location and/or place thatexists outside of an aircraft, wherein an aircraft is described below,in reference to FIG. 3 . Flow path 164 may include any channel, tube,hose, conduit, or the like suitable for facilitating fluidiccommunication, for example with a pouch cell. In some cases, flow path164 may include a check valve. As used in this disclosure, a “checkvalve” is a valve that permits flow of a fluid only in certain, forexample one, direction. In some cases check valve may be configured toallow flow of fluids substantially only away from first pouch cell 104and/or second pouch cell 128, while preventing back flow of vented fluidto first pouch cell 104 and/or second pouch cell 128. In some cases,check valve may include a duckbill check valve. In some cases, aduckbill check valve may have lips which are substantially in a shape ofa duckbill. Lips may be configured to open to allow forward flow (out ofthe lips), while remaining normally closed to prevent backflow (into thelips). In some cases, duckbill lips may be configured to automaticallyclose (remain normally closed), for example with use of a compliantelement, such as without limitation an elastomeric material, a spring,and the like. In some embodiments vent may include a mushroom poppetvalve. In some cases, a mushroom poppet valve may include a mushroomshaped poppet. Mushroom shaped poppet may seal against a sealingelement, for example a ring about an underside of a cap of the mushroomshaped poppet. In some cases, mushroom poppet valve may be loadedagainst sealing element, for example by way of a compliant element, suchas a spring. According to some embodiments, vent 160 may have a vacuumapplied to aid in venting of cell ejecta. Vacuum pressure differentialmay range from 0.1″Hg to 36″Hg. In some cases, vent 160 may beconfigured to provide fluidic communication through at least one ofejecta barrier 156 and/or first pouch 120 and/or second pouch 144. Insome cases, vent 160 may include a seam. Seam may be a seam of firstpouch 120 and/or second pouch 144. Alternatively or additionally; seammay be a seam of ejecta barrier 156.

With continued reference to FIG. 1 , in some embodiments stack batterypack 100 may additionally include a third pouch cell. Third pouch cellmay include at least a third pair of electrodes, at least a third pairof foil tabs welded to the third electrodes, at least a third insulatorlayer located substantially between the at least a third pair of foiltabs, a third pouch substantially encompassing the at least a third pairof foil tabs and the at least a third separator layer, and a thirdelectrolyte within the third pouch. Stack battery pack may include aplurality including any number of pouch cells. In some cases, each pouchcell of plurality of pouch cells is separated from adjacent pouch cellswith at least an ejecta barrier 156. Any pouch cell of plurality ofpouch cells in battery pack may include any component described in thisdisclosure, for example without limitation vents, valves, and the like.

Still referring to FIG. 1 , in some embodiments, first pouch cell 104and/or second pouch cell 128 may include Li ion batteries which mayinclude NCA, NMC, Lithium iron phosphate (LiFePO4) and Lithium ManganeseOxide (LMO) batteries, which may be mixed with another cathode chemistryto provide more specific power if the application requires Li metalbatteries, which have a lithium metal anode that provides high power ondemand, Li ion batteries that have a silicon, tin nanocrystals,graphite, graphene or titanate anode, or the like. Batteries and/orbattery modules may include without limitation batteries usingnickel-based chemistries such as nickel cadmium or nickel metal hydride,batteries using lithium-ion battery chemistries such as a nickel cobaltaluminum (NCA), nickel manganese cobalt (NMC), lithium iron phosphate(LiFePO4), lithium cobalt oxide (LCO), and/or lithium manganese oxide(LMO), batteries using lithium polymer technology, metal-air batteries.First pouch cell 104 and/or second pouch cell 128 may include lead-basedbatteries such as without limitation lead acid batteries and lead carbonbatteries. First pouch cell 104 and/or second pouch cell 128 may includelithium sulfur batteries, magnesium ion batteries, and/or sodium ionbatteries. Batteries may include solid state batteries orsupercapacitors or another suitable energy source. Batteries may beprimary or secondary or a combination of both. Additional disclosurerelated to batteries and battery modules may be found in co-owned U.S.patent applications entitled “SYSTEM AND METHOD FOR HIGH ENERGY DENSITYBATTERY MODULE” and “SYSTEMS AND METHODS FOR RESTRICTING POWER TO A LOADTO PREVENT ENGAGING CIRCUIT PROTECTION DEVICE FOR AN AIRCRAFT,” havingU.S. patent application Ser. Nos. 16/948,140 and 16/590,496respectively; the entirety of both applications are incorporated hereinby reference. Persons skilled in the art, upon reviewing the entirety ofthis disclosure, will be aware of various devices of components that maybe used as a battery module. In some cases, stack battery pack 100 isconstructed in a manner that vents ejecta, while preventing cell ejectafrom one pouch cell from interacting with another pouch cell.

With continued reference to FIG. 1 , stack battery pack 100 may includea sensor 168. Sensor 168 may include a sensor suite, for example asdescribed with reference to FIGS. 4-5 below. In some cases, sensor 168may be configured to sense battery pack data and transmit battery packdata to a data storage system, for example as described below inreference to FIGS. 4-5 . Additionally or alternatively, stack batterypack 100 is configured to power a propulsor component, wherein apropulsor component is described below in reference to FIG. 3 .

Referring now to FIG. 2 , a portion of an exemplary battery pack 200 isillustrated. Battery pack 200 may include a pouch cell 204. Pouch cell204 may include at least a pair of electrodes 208, at least a pair offoil tabs 212 in electrical communication with the electrodes 208, atleast an insulator layer 216 located substantially between the at leasta pair of foil tabs 212, a pouch 220 substantially encompassing the atleast a pair of foil tabs 212 and at least a portion of the at least aseparator layer 216, and a first electrolyte 224 within the pouch 220.Battery pack 200 may include an ejecta barrier 228. Ejecta barrier 228may configured to prevent cell ejecta from one pouch cell 204 fromreaching another pouch cell. In some cases, cell ejecta may include hotmatter, which if left uncontained could transfer heat to other, e.g.,neighboring, pouch cells. By preventing hot cell ejecta from reachingpouch cells ejecta barrier 228 may aid in preventing progression ofthermal runaway between battery cells within battery pack 200. In somecases, cell ejecta may include combustible materials, which if leftuncontained could settle upon other, e.g., neighboring, pouch cells.Combustible materials once combustion conditions are met may combustgenerating an exothermic reaction, which can induce thermal runaway onnearby battery cells. Combustion conditions can include presence ofoxygen, fuel, spark, flash point, fire point, and/or autoignitiontemperature. Battery pack 200 may include a vent 232. Vent 232 mayprovide for cell ejecta flow along a flow path 236. Vent may include acheck valve 240. Check valve 240 may be configured to allow for a flowpath and/or fluid in substantially one direction, for example away frompouch cell 204. In some cases, vent 232 may be configured to allow for aventing of cell ejecta from pouch cell 204 without substantially anyflow of cell ejecta toward the pouch cell 204, for example from otherbattery cells. According to some embodiments, battery pack 200 may beincorporated in an aircraft, for example a vertical take-off and landingaircraft.

Referring now to FIG. 3 , an exemplary embodiment of an aircraft 300 isillustrated. Aircraft 300 may include an electrically powered aircraft.In some embodiments, electrically powered aircraft may be an electricvertical takeoff and landing (eVTOL) aircraft. Electric aircraft may becapable of rotor-based cruising flight, rotor-based takeoff, rotor-basedlanding, fixed-wing cruising flight, airplane-style takeoff,airplane-style landing, and/or any combination thereof “Rotor-basedflight,” as described in this disclosure, is where the aircraftgenerated lift and propulsion by way of one or more powered rotorscoupled with an engine, such as a quadcopter, multi-rotor helicopter, orother vehicle that maintains its lift primarily using downward thrustingpropulsors. “Fixed-wing flight,” as described in this disclosure, iswhere the aircraft is capable of flight using wings and/or foils thatgenerate lift caused by the aircraft's forward airspeed and the shape ofthe wings and/or foils, such as airplane-style flight.

Still referring to FIG. 3 , aircraft 300 may include a fuselage 304. Asused in this disclosure a “fuselage” is the main body of an aircraft, orin other words, the entirety of the aircraft except for the cockpit,nose, wings, empennage, nacelles, any and all control surfaces, andgenerally contains an aircraft's payload. Fuselage 304 may comprisestructural elements that physically support the shape and structure ofan aircraft. Structural elements may take a plurality of forms, alone orin combination with other types. Structural elements may vary dependingon the construction type of aircraft and specifically, the fuselage.Fuselage 304 may comprise a truss structure. A truss structure may beused with a lightweight aircraft and may include welded aluminum tubetrusses. A truss, as used herein, is an assembly of beams that create arigid structure, often in combinations of triangles to createthree-dimensional shapes. A truss structure may alternatively comprisetitanium construction in place of aluminum tubes, or a combinationthereof. In some embodiments, structural elements may comprise aluminumtubes and/or titanium beams. In an embodiment, and without limitation,structural elements may include an aircraft skin. Aircraft skin may belayered over the body shape constructed by trusses. Aircraft skin maycomprise a plurality of materials such as aluminum, fiberglass, and/orcarbon fiber, the latter of which will be addressed in greater detaillater in this paper.

Still referring to FIG. 3 , aircraft 300 may include a plurality ofactuators 308. In an embodiment, actuator 308 may be mechanicallycoupled to an aircraft. As used herein, a person of ordinary skill inthe art would understand “mechanically coupled” to mean that at least aportion of a device, component, or circuit is connected to at least aportion of the aircraft via a mechanical coupling. Said mechanicalcoupling can include, for example, rigid coupling, such as beamcoupling, bellows coupling, bushed pin coupling, constant velocity,split-muff coupling, diaphragm coupling, disc coupling, donut coupling,elastic coupling, flexible coupling, fluid coupling, gear coupling, gridcoupling, Hirth joints, hydrodynamic coupling, jaw coupling, magneticcoupling, Oldham coupling, sleeve coupling, tapered shaft lock, twinspring coupling, rag joint coupling, universal joints, or anycombination thereof. As used in this disclosure an “aircraft” is vehiclethat may fly. As a non-limiting example, aircraft may include airplanes,helicopters, airships, blimps, gliders, paramotors, and the likethereof. In an embodiment, mechanical coupling may be used to connectthe ends of adjacent parts and/or objects of an electric aircraft.Further, in an embodiment, mechanical coupling may be used to join twopieces of rotating electric aircraft components.

With continued reference to FIG. 3 , a plurality of actuators 308 may beconfigured to produce a torque. As used in this disclosure a “torque” isa measure of force that causes an object to rotate about an axis in adirection. For example, and without limitation, torque may rotate anaileron and/or rudder to generate a force that may adjust and/or affectaltitude, airspeed velocity, groundspeed velocity, direction duringflight, and/or thrust. For example, plurality of actuators 308 mayinclude a component used to produce a torque that affects aircrafts'roll and pitch, such as without limitation one or more ailerons. An“aileron,” as used in this disclosure, is a hinged surface which formpart of the trailing edge of a wing in a fixed wing aircraft, and whichmay be moved via mechanical means such as without limitationservomotors, mechanical linkages, or the like. As a further example,plurality of actuators 308 may include a rudder, which may include,without limitation, a segmented rudder that produces a torque about avertical axis. Additionally or alternatively, plurality of actuators 308may include other flight control surfaces such as propulsors, rotatingflight controls, or any other structural features which can adjustmovement of aircraft 300. Plurality of actuators 308 may include one ormore rotors, turbines, ducted fans, paddle wheels, and/or othercomponents configured to propel a vehicle through a fluid mediumincluding, but not limited to air.

Still referring to FIG. 3 , plurality of actuators 308 may include atleast a propulsor component. As used in this disclosure a “propulsorcomponent” is a component and/or device used to propel a craft byexerting force on a fluid medium, which may include a gaseous mediumsuch as air or a liquid medium such as water. In an embodiment, when apropulsor twists and pulls air behind it, it may, at the same time, pushan aircraft forward with an amount of force and/or thrust. More airpulled behind an aircraft results in greater thrust with which theaircraft is pushed forward. Propulsor component may include any deviceor component that consumes electrical power on demand to propel anelectric aircraft in a direction or other vehicle while on ground orin-flight. In an embodiment, propulsor component may include a pullercomponent. As used in this disclosure a “puller component” is acomponent that pulls and/or tows an aircraft through a medium. As anon-limiting example, puller component may include a flight componentsuch as a puller propeller, a puller motor, a puller propulsor, and thelike. Additionally, or alternatively, puller component may include aplurality of puller flight components. In another embodiment, propulsorcomponent may include a pusher component. As used in this disclosure a“pusher component” is a component that pushes and/or thrusts an aircraftthrough a medium. As a non-limiting example, pusher component mayinclude a pusher component such as a pusher propeller, a pusher motor, apusher propulsor, and the like. Additionally, or alternatively, pusherflight component may include a plurality of pusher flight components.

In another embodiment, and still referring to FIG. 3 , propulsor mayinclude a propeller, a blade, or any combination of the two. A propellermay function to convert rotary motion from an engine or other powersource into a swirling slipstream which may push the propeller forwardsor backwards. Propulsor may include a rotating power-driven hub, towhich several radial airfoil-section blades may be attached, such thatan entire whole assembly rotates about a longitudinal axis. As anon-limiting example, blade pitch of propellers may be fixed at a fixedangle, manually variable to a few set positions, automatically variable(e.g. a “constant-speed” type), and/or any combination thereof asdescribed further in this disclosure. As used in this disclosure a“fixed angle” is an angle that is secured and/or substantially unmovablefrom an attachment point. For example, and without limitation, a fixedangle may be an angle of 2.2° inward and/or 1.7° forward. As a furthernon-limiting example, a fixed angle may be an angle of 3.6° outwardand/or 2.7° backward. In an embodiment, propellers for an aircraft maybe designed to be fixed to their hub at an angle similar to the threadon a screw makes an angle to the shaft; this angle may be referred to asa pitch or pitch angle which may determine a speed of forward movementas the blade rotates. Additionally or alternatively, propulsor componentmay be configured having a variable pitch angle. As used in thisdisclosure a “variable pitch angle” is an angle that may be moved and/orrotated. For example, and without limitation, propulsor component may beangled at a first angle of 3.3° inward, wherein propulsor component maybe rotated and/or shifted to a second angle of 1.7° outward.

Still referring to FIG. 3 , propulsor may include a thrust element whichmay be integrated into the propulsor. Thrust element may include,without limitation, a device using moving or rotating foils, such as oneor more rotors, an airscrew or propeller, a set of airscrews orpropellers such as contra-rotating propellers, a moving or flappingwing, or the like. Further, a thrust element, for example, can includewithout limitation a marine propeller or screw, an impeller, a turbine,a pump-jet, a paddle or paddle-based device, or the like.

With continued reference to FIG. 3 , plurality of actuators 308 mayinclude power sources, control links to one or more elements, fuses,and/or mechanical couplings used to drive and/or control any otherflight component. Plurality of actuators 308 may include a motor thatoperates to move one or more flight control components and/or one ormore control surfaces, to drive one or more propulsors, or the like,wherein a motor is described below. A motor may be driven by a motordrive, such as without limitation a direct current (DC) electric powerand may include, without limitation, brushless DC electric motors,switched reluctance motors, induction motors, or any combinationthereof. Alternatively or additionally, a motor drive may include aninverter. A motor drive may also include electronic speed controllers,inverters, or other components for regulating motor speed, rotationdirection, and/or dynamic braking.

Still referring to FIG. 3 , plurality of actuators 308 may include anenergy source. An energy source may include, for example, a generator, aphotovoltaic device, a fuel cell such as a hydrogen fuel cell, directmethanol fuel cell, and/or solid oxide fuel cell, an electric energystorage device (e.g. a capacitor, an inductor, and/or a battery). Anenergy source may also include a battery cell, or a plurality of batterycells connected in series into a module and each module connected inseries or in parallel with other modules. Energy source may include abattery pack, for example as described in reference to FIGS. 1-2 .Configuration of an energy source containing connected modules may bedesigned to meet an energy or power requirement and may be designed tofit within a designated footprint in an electric aircraft in whichsystem may be incorporated.

In an embodiment, and still referring to FIG. 3 , an energy source maybe used to provide a steady supply of electrical power to a load over aflight by an electric aircraft 300. For example, energy source may becapable of providing sufficient power for “cruising” and otherrelatively low-energy phases of flight. An energy source may also becapable of providing electrical power for some higher-power phases offlight as well, particularly when the energy source is at a high SOC, asmay be the case for instance during takeoff. In an embodiment, energysource may include an emergency power unit which may be capable ofproviding sufficient electrical power for auxiliary loads includingwithout limitation, lighting, navigation, communications, de-icing,steering or other systems requiring power or energy. Further, energysource may be capable of providing sufficient power for controlleddescent and landing protocols, including, without limitation, hoveringdescent or runway landing. As used herein the energy source may havehigh power density where electrical power an energy source can usefullyproduce per unit of volume and/or mass is relatively high. As used inthis disclosure, “electrical power” is a rate of electrical energy perunit time. An energy source may include a device for which power thatmay be produced per unit of volume and/or mass has been optimized, forinstance at an expense of maximal total specific energy density or powercapacity. Non-limiting examples of items that may be used as at least anenergy source include batteries used for starting applications includingLi ion batteries which may include NCA, NMC, Lithium iron phosphate(LiFePO4) and Lithium Manganese Oxide (LMO) batteries, which may bemixed with another cathode chemistry to provide more specific power ifthe application requires Li metal batteries, which have a lithium metalanode that provides high power on demand, Li ion batteries that have asilicon or titanite anode, energy source may be used, in an embodiment,to provide electrical power to an electric aircraft or drone, such as anelectric aircraft vehicle, during moments requiring high rates of poweroutput, including without limitation takeoff, landing, thermal de-icingand situations requiring greater power output for reasons of stability,such as high turbulence situations, as described in further detailbelow. A battery may include, without limitation a battery using nickelbased chemistries such as nickel cadmium or nickel metal hydride, abattery using lithium ion battery chemistries such as a nickel cobaltaluminum (NCA), nickel manganese cobalt (NMC), lithium iron phosphate(LiFePO4), lithium cobalt oxide (LCO), and/or lithium manganese oxide(LMO), a battery using lithium polymer technology, lead-based batteriessuch as without limitation lead acid batteries, metal-air batteries, orany other suitable battery. Persons skilled in the art, upon reviewingthe entirety of this disclosure, will be aware of various devices ofcomponents that may be used as an energy source.

Still referring to FIG. 3 , an energy source may include a plurality ofenergy sources, referred to herein as a module of energy sources. Modulemay include batteries connected in parallel or in series or a pluralityof modules connected either in series or in parallel designed to satisfyboth power and energy requirements. Connecting batteries in series mayincrease a potential of at least an energy source which may provide morepower on demand. High potential batteries may require cell matching whenhigh peak load is needed. As more cells are connected in strings, theremay exist a possibility of one cell failing which may increaseresistance in module and reduce overall power output as voltage of themodule may decrease as a result of that failing cell. Connectingbatteries in parallel may increase total current capacity by decreasingtotal resistance, and it also may increase overall amp-hour capacity.Overall energy and power outputs of at least an energy source may bebased on individual battery cell performance or an extrapolation basedon a measurement of at least an electrical parameter. In an embodimentwhere energy source includes a plurality of battery cells, overall poweroutput capacity may be dependent on electrical parameters of eachindividual cell. If one cell experiences high self-discharge duringdemand, power drawn from at least an energy source may be decreased toavoid damage to a weakest cell. Energy source may further include,without limitation, wiring, conduit, housing, cooling system and batterymanagement system. Persons skilled in the art will be aware, afterreviewing the entirety of this disclosure, of many different componentsof an energy source. Exemplary energy sources are disclosed in detail inU.S. patent application Ser. Nos. 16/948,157 and 16/948,140 bothentitled “SYSTEM AND METHOD FOR HIGH ENERGY DENSITY BATTERY MODULE” byS. Donovan et al., which are incorporated in their entirety herein byreference.

Still referring to FIG. 3 , according to some embodiments, an energysource may include an emergency power unit (EPU) (i.e., auxiliary powerunit). As used in this disclosure an “emergency power unit” is an energysource as described herein that is configured to power an essentialsystem for a critical function in an emergency, for instance withoutlimitation when another energy source has failed, is depleted, or isotherwise unavailable. Exemplary non-limiting essential systems includenavigation systems, such as MFD, GPS, VOR receiver or directional gyro,and other essential flight components, such as propulsors.

Still referring to FIG. 3 , another exemplary actuator may includelanding gear. Landing gear may be used for take-off and/orlanding/Landing gear may be used to contact ground while aircraft 300 isnot in flight. Exemplary landing gear is disclosed in detail in U.S.patent application Ser. No. 17/196,719 entitled “SYSTEM FOR ROLLINGLANDING GEAR” by R. Griffin et al., which is incorporated in itsentirety herein by reference.

Still referring to FIG. 3 , aircraft 300 may include a pilot control312, including without limitation, a hover control, a thrust control, aninceptor stick, a cyclic, and/or a collective control. As used in thisdisclosure a “collective control” is a mechanical control of an aircraftthat allows a pilot to adjust and/or control the pitch angle of theplurality of actuators 308. For example and without limitation,collective control may alter and/or adjust the pitch angle of all of themain rotor blades collectively. For example, and without limitationpilot control 312 may include a yoke control. As used in this disclosurea “yoke control” is a mechanical control of an aircraft to control thepitch and/or roll. For example and without limitation, yoke control mayalter and/or adjust the roll angle of aircraft 300 as a function ofcontrolling and/or maneuvering ailerons. In an embodiment, pilot control312 may include one or more foot-brakes, control sticks, pedals,throttle levels, and the like thereof. In another embodiment, andwithout limitation, pilot control 312 may be configured to control aprincipal axis of the aircraft. As used in this disclosure a “principalaxis” is an axis in a body representing one three dimensionalorientations. For example, and without limitation, principal axis ormore yaw, pitch, and/or roll axis. Principal axis may include a yawaxis. As used in this disclosure a “yaw axis” is an axis that isdirected towards the bottom of the aircraft, perpendicular to the wings.For example, and without limitation, a positive yawing motion mayinclude adjusting and/or shifting the nose of aircraft 300 to the right.Principal axis may include a pitch axis. As used in this disclosure a“pitch axis” is an axis that is directed towards the right laterallyextending wing of the aircraft. For example, and without limitation, apositive pitching motion may include adjusting and/or shifting the noseof aircraft 300 upwards. Principal axis may include a roll axis. As usedin this disclosure a “roll axis” is an axis that is directedlongitudinally towards the nose of the aircraft, parallel to thefuselage. For example, and without limitation, a positive rolling motionmay include lifting the left and lowering the right wing concurrently.

Still referring to FIG. 3 , pilot control 312 may be configured tomodify a variable pitch angle. For example, and without limitation,pilot control 312 may adjust one or more angles of attack of apropeller. As used in this disclosure an “angle of attack” is an anglebetween the chord of the propeller and the relative wind. For example,and without limitation angle of attack may include a propeller bladeangled 3.2°. In an embodiment, pilot control 312 may modify the variablepitch angle from a first angle of 2.71° to a second angle of 3.82°.Additionally or alternatively, pilot control 312 may be configured totranslate a pilot desired torque. For example, and without limitation,pilot control 312 may translate that a pilot's desired torque for apropeller be 160 lb. ft. of torque. As a further non-limiting example,pilot control 312 may introduce a pilot's desired torque for a propulsorto be 290 lb. ft. of torque. Additional disclosure related to pilotcontrol 312 may be found in U.S. patent application Ser. Nos. 17/001,845and 16/929,206 both of which are entitled “A HOVER AND THRUST CONTROLASSEMBLY FOR DUAL-MODE AIRCRAFT” by C. Spiegel et al., which areincorporated in their entirety herein by reference.

Still referring to FIG. 3 , aircraft 300 may include a loading system. Aloading system may include a system configured to load an aircraft ofeither cargo or personnel. For instance, some exemplary loading systemsmay include a swing nose, which is configured to swing the nose ofaircraft of the way thereby allowing direct access to a cargo baylocated behind the nose. A notable exemplary swing nose aircraft isBoeing 747. Additional disclosure related to loading systems can befound in U.S. patent application Ser. No. 17/137,594 entitled “SYSTEMAND METHOD FOR LOADING AND SECURING PAYLOAD IN AN AIRCRAFT” by R.Griffin et al., entirety of which in incorporated herein by reference.

Still referring to FIG. 3 , aircraft 300 may include a sensor 316.Sensor 316 may be configured to sense a characteristic of pilot control312. Sensor may be a device, module, and/or subsystem, utilizing anyhardware, software, and/or any combination thereof to sense acharacteristic and/or changes thereof, in an instant environment, forinstance without limitation a pilot control 312, which the sensor isproximal to or otherwise in a sensed communication with, and transmitinformation associated with the characteristic, for instance withoutlimitation digitized data. Sensor 316 may be mechanically and/orcommunicatively coupled to aircraft 300, including, for instance, to atleast a pilot control 312. Sensor 316 may be configured to sense acharacteristic associated with at least a pilot control 312. Anenvironmental sensor may include without limitation one or more sensorsused to detect ambient temperature, barometric pressure, and/or airvelocity, one or more motion sensors which may include withoutlimitation gyroscopes, accelerometers, inertial measurement unit (IMU),and/or magnetic sensors, one or more humidity sensors, one or moreoxygen sensors, or the like. Additionally or alternatively, sensor 316may include at least a geospatial sensor. Sensor 316 may be locatedinside an aircraft; and/or be included in and/or attached to at least aportion of the aircraft. Sensor may include one or more proximitysensors, displacement sensors, vibration sensors, and the like thereof.Sensor may be used to monitor the status of aircraft for both criticaland non-critical functions. Sensor may be incorporated into vehicle oraircraft or be remote.

Still referring to FIG. 3 , in some embodiments, sensor 316 may beconfigured to sense a characteristic associated with any pilot controldescribed in this disclosure. Non-limiting examples of a sensor 316 mayinclude an inertial measurement unit (IMU), an accelerometer, agyroscope, a proximity sensor, a pressure sensor, a light sensor, apitot tube, an air speed sensor, a position sensor, a speed sensor, aswitch, a thermometer, a strain gauge, an acoustic sensor, and anelectrical sensor. In some cases, sensor 316 may sense a characteristicas an analog measurement, for instance, yielding a continuously variableelectrical potential indicative of the sensed characteristic. In thesecases, sensor 316 may additionally comprise an analog to digitalconverter (ADC) as well as any additionally circuitry, such as withoutlimitation a Whetstone bridge, an amplifier, a filter, and the like. Forinstance, in some cases, sensor 316 may comprise a strain gageconfigured to determine loading of one or flight components, forinstance landing gear. Strain gage may be included within a circuitcomprising a Whetstone bridge, an amplified, and a bandpass filter toprovide an analog strain measurement signal having a high signal tonoise ratio, which characterizes strain on a landing gear member. An ADCmay then digitize analog signal produces a digital signal that can thenbe transmitted other systems within aircraft 300, for instance withoutlimitation a computing system, a pilot display, and a memory component.Alternatively or additionally, sensor 316 may sense a characteristic ofa pilot control 312 digitally. For instance in some embodiments, sensor316 may sense a characteristic through a digital means or digitize asensed signal natively. In some cases, for example, sensor 316 mayinclude a rotational encoder and be configured to sense a rotationalposition of a pilot control; in this case, the rotational encoderdigitally may sense rotational “clicks” by any known method, such aswithout limitation magnetically, optically, and the like.

Still referring to FIG. 3 , electric aircraft 300 may include at least amotor 320, which may be mounted on a structural feature of the aircraft.Design of motor 320 may enable it to be installed external to structuralmember (such as a boom, nacelle, or fuselage) for easy maintenanceaccess and to minimize accessibility requirements for the structure;this may improve structural efficiency by requiring fewer large holes inthe mounting area. In some embodiments, motor 320 may include two mainholes in top and bottom of mounting area to access bearing cartridge.Further, a structural feature may include a component of electricaircraft 300. For example, and without limitation structural feature maybe any portion of a vehicle incorporating motor 320, including anyvehicle as described in this disclosure. As a further non-limitingexample, a structural feature may include without limitation a wing, aspar, an outrigger, a fuselage, or any portion thereof; persons skilledin the art, upon reviewing the entirety of this disclosure, will beaware of many possible features that may function as at least astructural feature. At least a structural feature may be constructed ofany suitable material or combination of materials, including withoutlimitation metal such as aluminum, titanium, steel, or the like, polymermaterials or composites, fiberglass, carbon fiber, wood, or any othersuitable material. As a non-limiting example, at least a structuralfeature may be constructed from additively manufactured polymer materialwith a carbon fiber exterior; aluminum parts or other elements may beenclosed for structural strength, or for purposes of supporting, forinstance, vibration, torque or shear stresses imposed by at leastpropulsor 308. Persons skilled in the art, upon reviewing the entiretyof this disclosure, will be aware of various materials, combinations ofmaterials, and/or constructions techniques.

Still referring to FIG. 3 , electric aircraft 300 may include a verticaltakeoff and landing aircraft (eVTOL). As used herein, a verticaltake-off and landing (eVTOL) aircraft is one that can hover, take off,and land vertically. An eVTOL, as used herein, is an electricallypowered aircraft typically using an energy source, of a plurality ofenergy sources to power the aircraft. In order to optimize the power andenergy necessary to propel the aircraft. eVTOL may be capable ofrotor-based cruising flight, rotor-based takeoff, rotor-based landing,fixed-wing cruising flight, airplane-style takeoff, airplane-stylelanding, and/or any combination thereof. Rotor-based flight, asdescribed herein, is where the aircraft generated lift and propulsion byway of one or more powered rotors coupled with an engine, such as a“quad copter,” multi-rotor helicopter, or other vehicle that maintainsits lift primarily using downward thrusting propulsors. Fixed-wingflight, as described herein, is where the aircraft is capable of flightusing wings and/or foils that generate life caused by the aircraft'sforward airspeed and the shape of the wings and/or foils, such asairplane-style flight.

With continued reference to FIG. 3 , a number of aerodynamic forces mayact upon the electric aircraft 300 during flight. Forces acting onelectric aircraft 300 during flight may include, without limitation,thrust, the forward force produced by the rotating element of theelectric aircraft and acts parallel to the longitudinal axis. Anotherforce acting upon electric aircraft 300 may be, without limitation,drag, which may be defined as a rearward retarding force which is causedby disruption of airflow by any protruding surface of the electricaircraft 300 such as, without limitation, the wing, rotor, and fuselage.Drag may oppose thrust and acts rearward parallel to the relative wind.A further force acting upon electric aircraft 300 may include, withoutlimitation, weight, which may include a combined load of the electricaircraft 300 itself, crew, baggage, and/or fuel. Weight may pullelectric aircraft 300 downward due to the force of gravity. Anadditional force acting on electric aircraft 300 may include, withoutlimitation, lift, which may act to oppose the downward force of weightand may be produced by the dynamic effect of air acting on the airfoiland/or downward thrust from the propulsor 308 of the electric aircraft.Lift generated by the airfoil may depend on speed of airflow, density ofair, total area of an airfoil and/or segment thereof, and/or an angle ofattack between air and the airfoil. For example, and without limitation,electric aircraft 300 are designed to be as lightweight as possible.Reducing the weight of the aircraft and designing to reduce the numberof components is essential to optimize the weight. To save energy, itmay be useful to reduce weight of components of electric aircraft 300,including without limitation propulsors and/or propulsion assemblies. Inan embodiment, motor 320 may eliminate need for many external structuralfeatures that otherwise might be needed to join one component to anothercomponent. Motor 320 may also increase energy efficiency by enabling alower physical propulsor profile, reducing drag and/or wind resistance.This may also increase durability by lessening the extent to which dragand/or wind resistance add to forces acting on electric aircraft 300and/or propulsors.

Referring now to FIG. 4 , an embodiment of battery management system 400is presented. Battery management system 400 is be integrated in abattery pack configured for use in an electric aircraft. The batterymanagement system 400 is be integrated in a portion of the battery packor subassembly thereof. Battery management system 400 includes firstbattery management component 404 disposed on a first end of the batterypack. One of ordinary skill in the art will appreciate that there arevarious areas in and on a battery pack and/or subassemblies thereof thatmay include first battery management component 404. First batterymanagement component 404 may take any suitable form. In a non-limitingembodiment, first battery management component 404 may include a circuitboard, such as a printed circuit board and/or integrated circuit board,a subassembly mechanically coupled to at least a portion of the batterypack, standalone components communicatively coupled together, or anotherundisclosed arrangement of components; for instance, and withoutlimitation, a number of components of first battery management component404 may be soldered or otherwise electrically connected to a circuitboard. First battery management component may be disposed directly over,adjacent to, facing, and/or near a battery module and specifically atleast a portion of a battery cell. First battery management component404 includes first sensor suite 408. First sensor suite 408 isconfigured to measure, detect, sense, and transmit first plurality ofbattery pack data 428 to data storage system 420.

Referring again to FIG. 4 , battery management system 400 includessecond battery management component 412. Second battery managementcomponent 412 is disposed in or on a second end of battery pack 424.Second battery management component 412 includes second sensor suite416. Second sensor suite 416 may be consistent with the description ofany sensor suite disclosed herein. Second sensor suite 416 is configuredto measure second plurality of battery pack data 432. Second pluralityof battery pack data 432 may be consistent with the description of anybattery pack data disclosed herein. Second plurality of battery packdata 432 may additionally or alternatively include data not measured orrecorded in another section of battery management system 400. Secondplurality of battery pack data 432 may be communicated to additional oralternate systems to which it is communicatively coupled. Second sensorsuite 416 includes a moisture sensor consistent with any moisture sensordisclosed herein, namely moisture sensor 504.

With continued reference to FIG. 4 , first battery management component404 disposed in or on battery pack 424 may be physically isolated fromsecond battery management component 412 also disposed on or in batterypack 424. “Physical isolation”, for the purposes of this disclosure,refer to a first system's components, communicative coupling, and anyother constituent parts, whether software or hardware, are separatedfrom a second system's components, communicative coupling, and any otherconstituent parts, whether software or hardware, respectively. Firstbattery management component 404 and second battery management component408 may perform the same or different functions in battery managementsystem 400. In a non-limiting embodiment, the first and second batterymanagement components perform the same, and therefore redundantfunctions. If, for example, first battery management component 404malfunctions, in whole or in part, second battery management component408 may still be operating properly and therefore battery managementsystem 400 may still operate and function properly for electric aircraftin which it is installed. Additionally or alternatively, second batterymanagement component 408 may power on while first battery managementcomponent 404 is malfunctioning. One of ordinary skill in the art wouldunderstand that the terms “first” and “second” do not refer to either“battery management components” as primary or secondary. In non-limitingembodiments, first battery management component 404 and second batterymanagement component 408 may be powered on and operate through the sameground operations of an electric aircraft and through the same flightenvelope of an electric aircraft. This does not preclude one batterymanagement component, first battery management component 404, fromtaking over for second battery management component 408 if it were tomalfunction. In non-limiting embodiments, the first and second batterymanagement components, due to their physical isolation, may beconfigured to withstand malfunctions or failures in the other system andsurvive and operate. Provisions may be made to shield first batterymanagement component 404 from second battery management component 408other than physical location such as structures and circuit fuses. Innon-limiting embodiments, first battery management component 404, secondbattery management component 408, or subcomponents thereof may bedisposed on an internal component or set of components within batterypack 424.

Referring again to FIG. 4 , first battery management component 404 maybe electrically isolated from second battery management component 408.“Electrical isolation”, for the purposes of this disclosure, refer to afirst system's separation of components carrying electrical signals orelectrical energy from a second system's components. First batterymanagement component 404 may suffer an electrical catastrophe, renderingit inoperable, and due to electrical isolation, second batterymanagement component 408 may still continue to operate and functionnormally, managing the battery pack of an electric aircraft. Shieldingsuch as structural components, material selection, a combinationthereof, or another undisclosed method of electrical isolation andinsulation may be used, in non-limiting embodiments. For example, arubber or other electrically insulating material component may bedisposed between the electrical components of the first and secondbattery management components preventing electrical energy to beconducted through it, isolating the first and second battery managementcomponents from each other.

With continued reference to FIG. 4 , battery management system 400includes data storage system 420. Data storage system 420 is configuredto store first plurality of battery pack data 428 and second pluralityof battery pack data 432. Data storage system 420 may include adatabase. Data storage system 420 may include a solid-state memory ortape hard drive. Data storage system 420 may be communicatively coupledto first battery management component 404 and second battery managementcomponent 412 and may be configured to receive electrical signalsrelated to physical or electrical phenomenon measured and store thoseelectrical signals as first battery pack data 428 and second batterypack data 432, respectively. Alternatively, data storage system 420 mayinclude more than one discrete data storage systems that are physicallyand electrically isolated from each other. In this non-limitingembodiment, each of first battery management component 404 and secondbattery management component 412 may store first battery pack data 428and second battery pack data 432 separately. One of ordinary skill inthe art would understand the virtually limitless arrangements of datastores with which battery management system 400 could employ to storethe first and second plurality of battery pack data.

Referring again to FIG. 4 , data storage system 420 stores firstplurality of battery pack data 428 and second plurality of battery packdata 432. First plurality of battery pack data 428 and second pluralityof battery pack data 432 may include total flight hours that batterypack 424 and/or electric aircraft have been operating. The first andsecond plurality of battery pack data may include total energy flowedthrough battery pack 424. Data storage system 420 may be communicativelycoupled to sensors that detect, measure and store energy in a pluralityof measurements which may include current, voltage, resistance,impedance, coulombs, watts, temperature, or a combination thereof.Additionally or alternatively, data storage system 420 may becommunicatively coupled to a sensor suite consistent with thisdisclosure to measure physical and/or electrical characteristics. Datastorage system 420 may be configured to store first battery pack data428 and second battery pack data 432 wherein at least a portion of thedata includes battery pack maintenance history. Battery pack maintenancehistory may include mechanical failures and technician resolutionsthereof, electrical failures and technician resolutions thereof.Additionally, battery pack maintenance history may include componentfailures such that the overall system still functions. Data storagesystem 420 may store the first and second battery pack data thatincludes an upper voltage threshold and lower voltage thresholdconsistent with this disclosure. First battery pack data 428 and secondbattery pack data 432 may include a moisture level threshold. Themoisture level threshold may include an absolute, relative, and/orspecific moisture level threshold. Battery management system 400 may bedesigned to the Federal Aviation Administration (FAA)'s Design AssuranceLevel A (DAL-A), using redundant DAL-B subsystems.

Referring now to FIG. 5 , an embodiment of sensor suite 500 ispresented. The herein disclosed system and method may comprise aplurality of sensors in the form of individual sensors or a sensor suiteworking in tandem or individually. A sensor suite may include aplurality of independent sensors, as described herein, where any numberof the described sensors may be used to detect any number of physical orelectrical quantities associated with an aircraft power system or anelectrical energy storage system. Independent sensors may includeseparate sensors measuring physical or electrical quantities that may bepowered by and/or in communication with circuits independently, whereeach may signal sensor output to a control circuit such as a usergraphical interface. In a non-limiting example, there may be fourindependent sensors housed in and/or on battery pack 424 measuringtemperature, electrical characteristic such as voltage, amperage,resistance, or impedance, or any other parameters and/or quantities asdescribed in this disclosure. In an embodiment, use of a plurality ofindependent sensors may result in redundancy configured to employ morethan one sensor that measures the same phenomenon, those sensors beingof the same type, a combination of, or another type of sensor notdisclosed, so that in the event one sensor fails, the ability of batterymanagement system 400 and/or user to detect phenomenon is maintained andin a non-limiting example, a user alter aircraft usage pursuant tosensor readings.

In an embodiment, and still referring to FIG. 5 , sensor suite 500 mayinclude a moisture sensor 504. “Moisture”, as used in this disclosure,is the presence of water, this may include vaporized water in air,condensation on the surfaces of objects, or concentrations of liquidwater. Moisture may include humidity. “Humidity”, as used in thisdisclosure, is the property of a gaseous medium (almost always air) tohold water in the form of vapor. An amount of water vapor containedwithin a parcel of air can vary significantly. Water vapor is generallyinvisible to the human eye and may be damaging to electrical components.There are three primary measurements of humidity, absolute, relative,specific humidity. “Absolute humidity,” for the purposes of thisdisclosure, describes the water content of air and is expressed ineither grams per cubic meters or grams per kilogram. “Relativehumidity”, for the purposes of this disclosure, is expressed as apercentage, indicating a present stat of absolute humidity relative to amaximum humidity given the same temperature. “Specific humidity”, forthe purposes of this disclosure, is the ratio of water vapor mass tototal moist air parcel mass, where parcel is a given portion of agaseous medium. Moisture sensor 504 may be psychrometer. Moisture sensor504 may be a hygrometer. Moisture sensor 504 may be configured to act asor include a humidistat. A “humidistat”, for the purposes of thisdisclosure, is a humidity-triggered switch, often used to controlanother electronic device. Moisture sensor 504 may use capacitance tomeasure relative humidity and include in itself, or as an externalcomponent, include a device to convert relative humidity measurements toabsolute humidity measurements. “Capacitance”, for the purposes of thisdisclosure, is the ability of a system to store an electric charge, inthis case the system is a parcel of air which may be near, adjacent to,or above a battery cell.

With continued reference to FIG. 5 , sensor suite 500 may includeelectrical sensors 508. Electrical sensors 508 may be configured tomeasure voltage across a component, electrical current through acomponent, and resistance of a component. Electrical sensors 508 mayinclude separate sensors to measure each of the previously disclosedelectrical characteristics such as voltmeter, ammeter, and ohmmeter,respectively.

Alternatively or additionally, and with continued reference to FIG. 5 ,sensor suite 500 include a sensor or plurality thereof that may detectvoltage and direct the charging of individual battery cells according tocharge level; detection may be performed using any suitable component,set of components, and/or mechanism for direct or indirect measurementand/or detection of voltage levels, including without limitationcomparators, analog to digital converters, any form of voltmeter, or thelike. Sensor suite 500 and/or a control circuit incorporated thereinand/or communicatively connected thereto may be configured to adjustcharge to one or more battery cells as a function of a charge leveland/or a detected parameter. For instance, and without limitation,sensor suite 500 may be configured to determine that a charge level of abattery cell is high based on a detected voltage level of that batterycell or portion of the battery pack. Sensor suite 500 may alternativelyor additionally detect a charge reduction event, defined for purposes ofthis disclosure as any temporary or permanent state of a battery cellrequiring reduction or cessation of charging; a charge reduction eventmay include a cell being fully charged and/or a cell undergoing aphysical and/or electrical process that makes continued charging at acurrent voltage and/or current level inadvisable due to a risk that thecell will be damaged, will overheat, or the like. Detection of a chargereduction event may include detection of a temperature, of the cellabove a threshold level, detection of a voltage and/or resistance levelabove or below a threshold, or the like. Sensor suite 500 may includedigital sensors, analog sensors, or a combination thereof. Sensor suite500 may include digital-to-analog converters (DAC), analog-to-digitalconverters (ADC, A/D, A-to-D), a combination thereof, or other signalconditioning components used in transmission of a first plurality ofbattery pack data 428 to a destination over wireless or wiredconnection.

With continued reference to FIG. 5 , sensor suite 500 may includethermocouples, thermistors, thermometers, passive infrared sensors,resistance temperature sensors (RTD's), semiconductor based integratedcircuits (IC), a combination thereof or another undisclosed sensor type,alone or in combination. Temperature, for the purposes of thisdisclosure, and as would be appreciated by someone of ordinary skill inthe art, is a measure of the heat energy of a system. Temperature, asmeasured by any number or combinations of sensors present within sensorsuite 500, may be measured in Fahrenheit (° F.), Celsius (° C.), Kelvin(° K), or another scale alone or in combination. The temperaturemeasured by sensors may comprise electrical signals which aretransmitted to their appropriate destination wireless or through a wiredconnection.

With continued reference to FIG. 5 , sensor suite 500 may include asensor configured to detect gas that may be emitted during or after acell failure. “Cell failure”, for the purposes of this disclosure,refers to a malfunction of a battery cell, which may be anelectrochemical cell, that renders the cell inoperable for its designedfunction, namely providing electrical energy to at least a portion of anelectric aircraft. By products of cell failure 512 may include gaseousdischarge including oxygen, hydrogen, carbon dioxide, methane, carbonmonoxide, a combination thereof, or another undisclosed gas, alone or incombination. Further the sensor configured to detect vent gas fromelectrochemical cells may comprise a gas detector. For the purposes ofthis disclosure, a “gas detector” is a device used to detect a gas ispresent in an area. Gas detectors, and more specifically, the gas sensorthat may be used in sensor suite 500, may be configured to detectcombustible, flammable, toxic, oxygen depleted, a combination thereof,or another type of gas alone or in combination. The gas sensor that maybe present in sensor suite 500 may include a combustible gas,photoionization detectors, electrochemical gas sensors, ultrasonicsensors, metal-oxide-semiconductor (MOS) sensors, infrared imagingsensors, a combination thereof, or another undisclosed type of gassensor alone or in combination. Sensor suite 500 may include sensorsthat are configured to detect non-gaseous byproducts of cell failure 512including, in non-limiting examples, liquid chemical leaks includingaqueous alkaline solution, ionomer, molten phosphoric acid, liquidelectrolytes with redox shuttle and ionomer, and salt water, amongothers. Sensor suite 500 may include sensors that are configured todetect non-gaseous byproducts of cell failure 512 including, innon-limiting examples, electrical anomalies as detected by any of theprevious disclosed sensors or components.

With continued reference to FIG. 5 , sensor suite 500 may be configuredto detect events where voltage nears an upper voltage threshold or lowervoltage threshold. The upper voltage threshold may be stored in datastorage system 420 for comparison with an instant measurement taken byany combination of sensors present within sensor suite 500. The uppervoltage threshold may be calculated and calibrated based on factorsrelating to battery cell health, maintenance history, location withinbattery pack, designed application, and type, among others. Sensor suite500 may measure voltage at an instant, over a period of time, orperiodically. Sensor suite 500 may be configured to operate at any ofthese detection modes, switch between modes, or simultaneous measure inmore than one mode. First battery management component 404 may detectthrough sensor suite 500 events where voltage nears the lower voltagethreshold. The lower voltage threshold may indicate power loss to orfrom an individual battery cell or portion of the battery pack. Firstbattery management component 404 may detect through sensor suite 500events where voltage exceeds the upper and lower voltage threshold.Events where voltage exceeds the upper and lower voltage threshold mayindicate battery cell failure or electrical anomalies that could lead topotentially dangerous situations for aircraft and personnel that may bepresent in or near its operation.

Referring now to FIG. 6 , an exemplary method 600 of manufacture for astack battery pack for an electric vertical take-off and landingaircraft is illustrated. At step 605, method 600 includes receiving afirst pouch cell 104. First pouch cell 104 includes any of the firstpouch cell 104 as described above, in reference to FIGS. 1-5 . In anembodiment, and without limitation, first pouch cell 104 may include afirst pair of electrodes 108. First pair of electrodes 108 includes anyof the first pair of electrodes 108 as described above, in reference toFIGS. 1-5 . In another embodiment, and without limitation, first pouchcell 104 may include a first pair of foil tabs 112. First pair of foiltabs 112 includes any of the first pair of foil tabs 112 as describedabove, in reference to FIGS. 1-5 . In another embodiment, and withoutlimitation, first pouch cell 104 may include a first insulator layer116. First insulator layer 120 includes any of the first insulator layer116 as described above, in reference to FIGS. 1-7 . IN anotherembodiment, and without limitation, first pouch cell 104 may include afirst pouch 120. First pouch 120 includes any of the first pouch 120 asdescribed above, in reference to FIGS. 1-5 . In another embodiment, andwithout limitation, first pouch cell 104 may include a first electrolyte124. First electrolyte 124 includes any of the first electrolyte 124 asdescribed above, in reference to FIGS. 1-5 .

Still referring to FIG. 6 , at step 610, method 600 includes obtaining asecond cell pouch 128. Second pouch cell 128 includes any of the secondpouch cell 128 as described above, in reference to FIGS. 1-5 . In anembodiment, and without limitation, second pouch cell 128 may include asecond pair of electrodes 132. Second pair of electrodes 132 includesany of the second pair of electrodes 132 as described above, inreference to FIGS. 1-5 . In another embodiment, and without limitation,second pouch cell 128 may include a second pair of foil tabs 136. Secondpair of foil tabs 136 includes any of the second pair of foil tabs 136as described above, in reference to FIGS. 1-5 . In another embodiment,and without limitation, second pouch cell 128 may include a secondinsulator layer 140. Second insulator layer 140 includes any of thesecond insulator layer 140 as described above, in reference to FIGS. 1-7. IN another embodiment, and without limitation, second pouch cell 128may include a second pouch 144. Second pouch 144 includes any of thesecond pouch 144 as described above, in reference to FIGS. 1-5 . Inanother embodiment, and without limitation, second pouch cell 128 mayinclude a second electrolyte 148. Second electrolyte 148 includes any ofthe second electrolyte 148 as described above, in reference to FIGS. 1-5. In an embodiment, and without limitation, second cell pouch 128 may bealigned along a vertical axis 152. Vertical axis 152 includes any of thevertical axis 152 as described above, in reference to FIGS. 1-5 .

Still referring to FIG. 6 , at step 615, method 600 includes locating anejecta barrier 156. Ejecta barrier 156 includes any of the ejectabarrier as described above, in reference to FIGS. 1-5 . In anembodiment, and without limitation, ejecta barrier 156 may be configuredto be substantially impermeable to a cell ejecta from first pouch cell104. Cell ejecta includes any of the cell ejecta as described above, inreference to FIGS. 1-5 .

Still referring to FIG. 6 , at step 620, method 600 includes configuringa vent 160 to vent cell ejecta. Vent 160 includes any of the vent 160 asdescribed above, in reference to FIGS. 1-5 .

Still referring to FIG. 6 , at step 625, method 600 includes configuringstack battery pack 100 to power a propulsor component. Stack batterypack 100 includes any of the stack battery pack 100 as described above,in reference to FIGS. 1-5 . Propulsor component includes any of thepropulsor component as described above, in reference to FIGS. 1-5 .

It is to be noted that any one or more of the aspects and embodimentsdescribed herein may be conveniently implemented using one or moremachines (e.g., one or more computing devices that are utilized as auser computing device for an electronic document, one or more serverdevices, such as a document server, etc.) programmed according to theteachings of the present specification, as will be apparent to those ofordinary skill in the computer art. Appropriate software coding canreadily be prepared by skilled programmers based on the teachings of thepresent disclosure, as will be apparent to those of ordinary skill inthe software art. Aspects and implementations discussed above employingsoftware and/or software modules may also include appropriate hardwarefor assisting in the implementation of the machine executableinstructions of the software and/or software module.

Such software may be a computer program product that employs amachine-readable storage medium. A machine-readable storage medium maybe any medium that is capable of storing and/or encoding a sequence ofinstructions for execution by a machine (e.g., a computing device) andthat causes the machine to perform any one of the methodologies and/orembodiments described herein. Examples of a machine-readable storagemedium include, but are not limited to, a magnetic disk, an optical disc(e.g., CD, CD-R, DVD, DVD-R, etc.), a magneto-optical disk, a read-onlymemory “ROM” device, a random access memory “RAM” device, a magneticcard, an optical card, a solid-state memory device, an EPROM, an EEPROM,and any combinations thereof. A machine-readable medium, as used herein,is intended to include a single medium as well as a collection ofphysically separate media, such as, for example, a collection of compactdiscs or one or more hard disk drives in combination with a computermemory. As used herein, a machine-readable storage medium does notinclude transitory forms of signal transmission.

Such software may also include information (e.g., data) carried as adata signal on a data carrier, such as a carrier wave. For example,machine-executable information may be included as a data-carrying signalembodied in a data carrier in which the signal encodes a sequence ofinstruction, or portion thereof, for execution by a machine (e.g., acomputing device) and any related information (e.g., data structures anddata) that causes the machine to perform any one of the methodologiesand/or embodiments described herein.

Examples of a computing device include, but are not limited to, anelectronic book reading device, a computer workstation, a terminalcomputer, a server computer, a handheld device (e.g., a tablet computer,a smartphone, etc.), a web appliance, a network router, a networkswitch, a network bridge, any machine capable of executing a sequence ofinstructions that specify an action to be taken by that machine, and anycombinations thereof. In one example, a computing device may includeand/or be included in a kiosk.

FIG. 7 shows a diagrammatic representation of one embodiment of acomputing device in the exemplary form of a computer system 700 withinwhich a set of instructions for causing a control system to perform anyone or more of the aspects and/or methodologies of the presentdisclosure may be executed. It is also contemplated that multiplecomputing devices may be utilized to implement a specially configuredset of instructions for causing one or more of the devices to performany one or more of the aspects and/or methodologies of the presentdisclosure. Computer system 700 includes a processor 704 and a memory708 that communicate with each other, and with other components, via abus 712. Bus 712 may include any of several types of bus structuresincluding, but not limited to, a memory bus, a memory controller, aperipheral bus, a local bus, and any combinations thereof, using any ofa variety of bus architectures.

Processor 704 may include any suitable processor, such as withoutlimitation a processor incorporating logical circuitry for performingarithmetic and logical operations, such as an arithmetic and logic unit(ALU), which may be regulated with a state machine and directed byoperational inputs from memory and/or sensors; processor 704 may beorganized according to Von Neumann and/or Harvard architecture as anon-limiting example. Processor 704 may include, incorporate, and/or beincorporated in, without limitation, a microcontroller, microprocessor,digital signal processor (DSP), Field Programmable Gate Array (FPGA),Complex Programmable Logic Device (CPLD), Graphical Processing Unit(GPU), general purpose GPU, Tensor Processing Unit (TPU), analog ormixed signal processor, Trusted Platform Module (TPM), a floating pointunit (FPU), and/or system on a chip (SoC).

Memory 708 may include various components (e.g., machine-readable media)including, but not limited to, a random-access memory component, a readonly component, and any combinations thereof. In one example, a basicinput/output system 716 (BIOS), including basic routines that help totransfer information between elements within computer system 700, suchas during start-up, may be stored in memory 708. Memory 708 may alsoinclude (e.g., stored on one or more machine-readable media)instructions (e.g., software) 720 embodying any one or more of theaspects and/or methodologies of the present disclosure. In anotherexample, memory 708 may further include any number of program modulesincluding, but not limited to, an operating system, one or moreapplication programs, other program modules, program data, and anycombinations thereof.

Computer system 700 may also include a storage device 724. Examples of astorage device (e.g., storage device 724) include, but are not limitedto, a hard disk drive, a magnetic disk drive, an optical disc drive incombination with an optical medium, a solid-state memory device, and anycombinations thereof. Storage device 724 may be connected to bus 712 byan appropriate interface (not shown). Example interfaces include, butare not limited to, SCSI, advanced technology attachment (ATA), serialATA, universal serial bus (USB), IEEE 1394 (FIREWIRE), and anycombinations thereof. In one example, storage device 724 (or one or morecomponents thereof) may be removably interfaced with computer system 700(e.g., via an external port connector (not shown)). Particularly,storage device 724 and an associated machine-readable medium 728 mayprovide nonvolatile and/or volatile storage of machine-readableinstructions, data structures, program modules, and/or other data forcomputer system 700. In one example, software 720 may reside, completelyor partially, within machine-readable medium 728. In another example,software 720 may reside, completely or partially, within processor 704.

Computer system 700 may also include an input device 732. In oneexample, a user of computer system 700 may enter commands and/or otherinformation into computer system 700 via input device 732. Examples ofan input device 732 include, but are not limited to, an alpha-numericinput device (e.g., a keyboard), a pointing device, a joystick, agamepad, an audio input device (e.g., a microphone, a voice responsesystem, etc.), a cursor control device (e.g., a mouse), a touchpad, anoptical scanner, a video capture device (e.g., a still camera, a videocamera), a touchscreen, and any combinations thereof. Input device 732may be interfaced to bus 712 via any of a variety of interfaces (notshown) including, but not limited to, a serial interface, a parallelinterface, a game port, a USB interface, a FIREWIRE interface, a directinterface to bus 712, and any combinations thereof. Input device 732 mayinclude a touch screen interface that may be a part of or separate fromdisplay 736, discussed further below. Input device 732 may be utilizedas a user selection device for selecting one or more graphicalrepresentations in a graphical interface as described above.

A user may also input commands and/or other information to computersystem 700 via storage device 724 (e.g., a removable disk drive, a flashdrive, etc.) and/or network interface device 740. A network interfacedevice, such as network interface device 740, may be utilized forconnecting computer system 700 to one or more of a variety of networks,such as network 744, and one or more remote devices 748 connectedthereto. Examples of a network interface device include, but are notlimited to, a network interface card (e.g., a mobile network interfacecard, a LAN card), a modem, and any combination thereof. Examples of anetwork include, but are not limited to, a wide area network (e.g., theInternet, an enterprise network), a local area network (e.g., a networkassociated with an office, a building, a campus or other relativelysmall geographic space), a telephone network, a data network associatedwith a telephone/voice provider (e.g., a mobile communications providerdata and/or voice network), a direct connection between two computingdevices, and any combinations thereof. A network, such as network 744,may employ a wired and/or a wireless mode of communication. In general,any network topology may be used. Information (e.g., data, software 720,etc.) may be communicated to and/or from computer system 700 via networkinterface device 740.

Computer system 700 may further include a video display adapter 752 forcommunicating a displayable image to a display device, such as displaydevice 736. Examples of a display device include, but are not limitedto, a liquid crystal display (LCD), a cathode ray tube (CRT), a plasmadisplay, a light emitting diode (LED) display, and any combinationsthereof. Display adapter 752 and display device 736 may be utilized incombination with processor 704 to provide graphical representations ofaspects of the present disclosure. In addition to a display device,computer system 700 may include one or more other peripheral outputdevices including, but not limited to, an audio speaker, a printer, andany combinations thereof. Such peripheral output devices may beconnected to bus 712 via a peripheral interface 756. Examples of aperipheral interface include, but are not limited to, a serial port, aUSB connection, a FIREWIRE connection, a parallel connection, and anycombinations thereof.

The foregoing has been a detailed description of illustrativeembodiments of the invention. Various modifications and additions can bemade without departing from the spirit and scope of this invention.Features of each of the various embodiments described above may becombined with features of other described embodiments as appropriate inorder to provide a multiplicity of feature combinations in associatednew embodiments. Furthermore, while the foregoing describes a number ofseparate embodiments, what has been described herein is merelyillustrative of the application of the principles of the presentinvention. Additionally, although particular methods herein may beillustrated and/or described as being performed in a specific order, theordering is highly variable within ordinary skill to achieve systems andmethods according to the present disclosure. Accordingly, thisdescription is meant to be taken only by way of example, and not tootherwise limit the scope of this invention.

Exemplary embodiments have been disclosed above and illustrated in theaccompanying drawings. It will be understood by those skilled in the artthat various changes, omissions and additions may be made to that whichis specifically disclosed herein without departing from the spirit andscope of the present invention.

1. A stack battery pack for an electric vertical take-off and landingaircraft comprising: a first pouch cell comprising a first top surfaceand a first bottom surface; a second pouch cell comprising a second topsurface and a second bottom surface, wherein the first pouch cell andthe second pouch cell are aligned along a vertical axis such that thefirst bottom surface is adjacent to the second top surface, wherein thesecond pouch cell comprises an outer surface having a nickel coating; anejecta barrier located between the first pouch cell and the second pouchcell, wherein the ejecta barrier is configured to be substantiallyimpermeable to a cell ejecta from the first pouch cell, and wherein theejecta barrier comprises at least a silver material and configured toabsorb lithium-based compounds; a vent configured to vent the cellejecta; and a tube in fluid communication with the vent and defining aflow path, wherein the flow path is cordoned away from contact with thesecond pouch cell, wherein the tube is configured to receive the ventedcell ejecta from the first pouch cell and transport it along the flowpath, and wherein the tube includes a check valve configured to preventbackflow of the cell ejecta to the first pouch cell; wherein the stackbattery pack is configured to power a propulsor component.
 2. Thebattery pack of claim 1, wherein the first pouch cell comprises: a firstpair of electrodes; a first pair of foil tabs welded to the firstelectrodes; a first insulator layer located substantially between thefirst pair of foil tabs; a first pouch substantially encompassing thefirst pair of foil tabs and the first insulator layer; and a firstelectrolyte within the first pouch.
 3. The battery pack of claim 1,wherein the second pouch cell comprises: a second pair of electrodes; asecond pair of foil tabs welded to the second electrodes; a secondinsulator layer located substantially between the second pair of foiltabs; a second pouch substantially encompassing the second pair of foiltabs and the second insulator layer; and a second electrolyte within thesecond pouch.
 4. The battery pack of claim 1, wherein the lithophilicmaterial comprises at least one of silver and gold.
 5. The battery packof claim 1, wherein the vent is further configured to vent the cellejecta from the first pouch cell along the flow path under a vacuumpressure.
 6. The battery pack of claim 5, wherein the flow path extendsfrom the first pouch cell to a location exterior to an electric verticaltake-off and landing aircraft.
 7. The battery pack of claim 1, whereinthe check valve includes a duckbill check valve.
 8. The battery pack ofclaim 1, wherein the battery pack further comprises a sensor, whereinthe sensor is configured to: sense a battery pack datum; and transmitthe battery pack datum to a data storage system.
 9. The battery pack ofclaim 8, wherein the sensor is configured to detect cell failure. 10.The battery pack of claim 1, wherein the battery pack further comprisesa first gas sensor and a second gas sensor with each configured toindependently detect a gaseous byproduct discharge as a result of cellfailure and thereby provide detection redundancy for the same gaseousbyproduct discharge in the event of failure of one of the sensors.
 11. Amethod of manufacturing a stack battery pack for an electric verticaltake-off and landing aircraft comprising: receiving a first pouch cellcomprising a first top surface and a first bottom surface; obtaining asecond pouch cell comprising a second top surface and a second bottomsurface, wherein the first pouch cell and the second pouch cell arealigned such that the first bottom surface is adjacent to the second topsurface, wherein the second pouch cell comprises an outer surface havinga nickel coating; locating an ejecta barrier between the first pouchcell and the second pouch cell, wherein the ejecta barrier is configuredto be substantially impermeable to a cell ejecta from the first pouchcell and wherein the ejecta barrier comprises at least a silver materialand is configured to absorb lithium-based compounds; configuring a ventof the first pouch cell to vent the cell ejecta from the first pouchcell; fluidly communicating a tube with the vent, wherein the tubedefines a flow path wherein the flow path is cordoned away from contactwith the second pouch cell, wherein the tube is configured to receivethe vented cell ejecta from the first pouch cell and transport it alongthe fluid path, and wherein the tube includes a check valve configuredto prevent backflow of the cell ejecta to the first pouch cell; andconfiguring the stack battery pack to power a propulsor component. 12.The method of claim 11, wherein the first pouch cell comprises: a firstpair of electrodes; a first pair of foil tabs welded to the firstelectrodes; a first insulator layer located substantially between thefirst pair of foil tabs; a first pouch substantially encompassing thefirst pair of foil tabs and the first insulator layer; and a firstelectrolyte within the first pouch.
 13. The method of claim 11, whereinthe second pouch cell comprises: a second pair of electrodes; a secondpair of foil tabs welded to the second electrodes; a second insulatorlayer located substantially between the second pair of foil tabs; asecond pouch substantially encompassing the second pair of foil tabs andthe second insulator layer; and a second electrolyte within the secondpouch.
 14. The method of claim 11, wherein lithophilic materialcomprises at least one of silver and gold.
 15. The method of claim 11,wherein configuring the vent further comprises venting the cell ejectafrom the first pouch cell along the flow path under a vacuum pressure.16. The method of claim 15, wherein the flow path extends from the firstpouch cell to a location exterior to an electric vertical take-off andlanding aircraft.
 17. The method of claim 11, wherein the check valveincludes a duckbill check valve.
 18. The method of claim 1, wherein themethod further comprises: installing a sensor, wherein the sensor isconfigured to: sense a battery pack datum; and transmit the battery packdatum to a data storage system.
 19. The method of claim 18, whereinsensing a battery pack datum further comprises to detecting a cellfailure.
 20. The method of claim 11, wherein the battery pack furthercomprises a first gas sensor and a second gas sensor with eachconfigured to independently detect a gaseous byproduct discharge as aresult of cell failure and thereby provide detection redundancy for thesame gaseous byproduct discharge in the event of failure of one of thesensors.